Conventional electrocardiographic instruments are configured to acquire and record biosignals such as biopotential signals relating to electrical activities of the heart. It is conventionally accepted that a large fraction of the total signal collected by such instruments is considered devoid of biological information. However, hidden within the full spectrum of physiologic signals emitted from the human body are information that can be used to pinpoint and distinguish disease.
Because these information can be captured in physiologic signals having signal power comparable to, or lower than, the noise floor of conventional electrocardiographic instruments, such information are difficult to extract, or not discernible, from the measured signals of these instruments. In some instances, the signal of interests has an order of magnitude of a few micro-Volts, and in other instances, even smaller. At such levels, interference from external energy sources such as man-made radiofrequency transmission and those that occur naturally as well as those from internal circuitries of the measurement instrument itself can affect the acquisition and recording of such information.
What are needed are devices, systems and methods that overcome challenges in the present art, some of which are described above.